Sciencemadness Discussion Board

Wanted-bis-BOC L-arginine, protected at guanidine

tsathoggua1 - 15-7-2017 at 11:20

I'm looking to source some L-arginine with the amine end free, but the guanidine portion of the molecule protected by BOC or tBOC, am willing if anyone has this to either trade reagents or buy directly (some TFA would be helpful also although this I can get elsewhere if needs be) for a peptide synthesis. Its a fairly small linear peptide and its being much cheaper to make via liquid-phase methods than outsourcing to a peptide synthesis company, given the size of it and simplicity of synthesis once the protected L-arginine is on hand. And another reason I don't particularly wish to outsource to a peptide manufacture company is that way, I'd learn nothing during the process whilst doing it myself I'll actually gain some experience and knowledge (this would be my first peptide synthesis)

Alternatively if anybody has any suggestions either for protection of the guanidine end of the amino-acid, or for protection of the amine end with a protecting group which can be removed separately from the bis-BOC/bis-tBOC-guanidinyl-L-arginine in-house, or else with the guanidine end of things bound to a resin for solid-phase synthesis. Am aiming at a yield of a gram to 5-10g (or, if suitable methods are available for starting with plain L-arginine, which I have quite a lot of on the lab shelf, plus the other amino acid in the dipeptide I have in mind,) FMOC would do if BOC/tBOC-guanidinyl-L-arginine cannot be found but due to the bulk of the FMOC group and correspondingly lower yield of the peptide per currency unit expended on the protected aminoacid or if anyone here has something suitable and wishes to trade, same principle applying of course, then BOC/tBOC would be preferred as the protecting group.


If nobody can help directly, could somebody be kind enough to suggest reputable peptide companies that I might approach for the requisite amino-acid, because, this being my first venture into synthesis of peptides, I don't know who will deal with individuals and who are the uni/industry-snobs who wouldn't piss in our faces, as private lab owners if our eyeballs were covered in acid.

[Edited on 15-7-2017 by tsathoggua1]

[Edited on 15-7-2017 by tsathoggua1]

rh0dium - 24-7-2017 at 07:05

I'm not terrible knowledgeable on peptide synthesis but the company (ChemImpex) where I get some of my reagents carries thousands of protected amino acids and peptide building blocks. I didn't have any issues setting up an individual account. www.chemimpex.com

[Edited on 24-7-2017 by rh0dium]

tsathoggua1 - 24-7-2017 at 10:58

Thank you. I'm totally new to peptide sythesis, this would be my first.

I observed an interesting article surfing wikipedia as I often do, to give me leads with which to satiate my everlasting thirst for knowledge and information, and I came across this intriguing dipeptide, L-tyrosyl-L-arginine, or kyotorphin. Its a highly atypical opioidergic peptide, which has no direct binding to MOR, DOR, KOR or ORL-1, but rather acts as a secretagogue for methionine-enkephalin and also simultaneously stabilizing this endogenous neuropeptide from degradation.

I've been wondering how it may perform in opioid-dependent pain patients, such as myself, in order to assist in lowering dosages whilst maintaining analgesia and attenuating withdrawals et cetera. And additionally, its a completely novel mode of action on the opioidergic system, and being so simple in structure thought this worth the effort to synthesize and bioassay.


Question-from which direction is the numbering with arginine? Alpha carbon far right or at the guanidine end?

[Edited on 24-7-2017 by tsathoggua1]